The present invention relates in general to a roll forming mill, and more particularly to a roll forming mill capable of uniformly adjusting both the horizontal and the vertical separations between matching upper and lower roller dies.
Roll forming machinery usually has a plurality of sets of rolls, usually arranged in upper and lower pairs, and usually spaced apart along the length of the machine on roller die stands. Typically, the roller dies at one die stand will produce a continuous formation in the web, and the roller dies of the next die stand will produce another formation, or for example increase the angle of the formation which has already been started at the previous die stand and so on.
A wide variety of commercial and other products are made on such roll forming machines, such as roof decking siding, and a large number of components for consumer equipment. The shapes may simply be webs with edge formations formed along one edge or both, or may be C sections or U sections but in many cases consist of relatively complex formations with longitudinal formations being formed along the length of the web, side by side.
Generally speaking at each die stand of rolls there are two lower dies and two upper dies arranged in pairs, to form the web on either side of a central web axis. The lower dies engage the underside of the web and the upper dies engage the upper side of the web. The dies have circular shapes, and are mounted on rotatable axles so that the dies can rotate at the same speed as the sheet metal.
A gear drive mechanism is coupled to the dies so as to drive them at the speed of the sheet metal.
Each set of such roller dies must be designed to provide a particular formation in the web. In addition, each pair of dies must have a clearance between them determined by the thickness of the web.
Thus where it is desired to discontinue working on a web of one thickness, and to then run a web of another thickness through the dies, each pair of roller dies must be readjusted to a new clearance, to accommodate the new thickness of the new web. This involves costly down time, in order to make the fine adjustments.
Generally speaking, it is not possible to adjust the clearances of the roller dies during the actual operation of the machine, and the best that can be done is that in the initial set up for any particular run, the machinist will set the die clearances to a predetermined average web thickness. The results obtained in this way however are not always entirely satisfactory.
It would in theory, be desirable to provide for automatic self-adjustment of the spacings or clearances between the pairs of dies in each die stand. However, due to the shaping of the dies there are difficulties in such adjustments. Usually the dies will have two surfaces, one of the surfaces being more or less horizontal, or at least parallel to the plane of the web itself, and the other of the surfaces being at a web-forming angle.
Another set of problems arises if it is desired to use the same roller dies, to form a web having a width which is greater, or narrower than a preceding web.
In the past each of the die stands would have to be manually moved further apart, or closer together, to take in to account the width of the new web to be processed. However, it was time consuming to dismantle the arrangement of dies for one web width, and then reassemble the dies with a greater or lesser umber of rolls between them to suit the new web width. In addition, this was awkward and time-consuming manual work.
It is therefore desirable to provide for roller die stands arranged- in pairs, in which one of each of the die stands in each of the pairs shall be transversely moveable relative to the other.
Given both die clearance adjustment, and die stand width adjustment, it would be possible, using one set of roller die stands and dies, to provide for the processing of webs both of different thicknesses, and also of different widths. This enables a manufacturer to produce a standard rolled form section such as a xe2x80x9cCxe2x80x9d section in a variety of widths and in a variety of gauges, from a single machine. This would reduce the capital investment in machinery. In addition would reduce the down time required for change over from one web to another and also reduce the need for skilled labor.
Unfortunately, the cost of a new machine with the desirable features outlined above may not be within the reach for many companies. A way to circumvent this difficulty is to provide a modification or retro-fit kit to update existing Roll Forming Machines. This type of retro-fit would update the older machines with current technology and allow for motorized adjustment of the dies to accommodate for various thickness of a web. This would decrease the amount of downtime, the cost of manual labor and increase productivity of these older machines. Thus enabling them to remain competitive.
A further problem arises with roll forming certain sections, particularly sections which have the shape of a letter C with in turned flanges, or a partially closed-in box section.
In this type of section, the two edges or flanges of the C, or partially closed-in box, are turned inwardly. This is usually done by roll forming the edge flanges first, and then roll forming the C bends later, i.e., downstream. Special dies are required to form the last bends, and it is desirable to provide for adjustment of these dies. Adjustment of such dies in this location however, to accommodate variations in web thickness and to form different sizes of C-section presents further problems.
With the foregoing problems and concerns in mind, the present invention therefore seeks to provide for the efficient and simultaneous adjustment of a plurality of die stands, both in new roll forming mills as well as a retro-fit to older, existing roll forming mills.
According to one embodiment of the present invention, a rolling mill apparatus for forming a web of material includes a die stand having an upper die assembly and a lower die assembly, the die stand bending the web to a predetermined formation angle as the web passes between the upper die assembly and the lower die assembly. A movement apparatus is utilized for selectively moving the upper die assembly in a vertical direction, thereby adjusting a vertical clearance between the upper die assembly and the lower die assembly. A pin is fixed to the upper die assembly and a cam block having a groove formed at a predetermined orientation angle is also provided. The pin travels in the angled groove when the upper die assembly is moved in the vertical direction and causes the upper die assembly to move horizontally. The predetermined orientation angle of the block is approximately equal to the predetermined formation angle.